1. Field of the Invention
The present disclosure relates to an organic light-emitting display device and a method of manufacturing the same, and more particularly, to an organic light-emitting display device whose manufacturing costs can be reduced by simplifying the manufacturing process, and a method of manufacturing the same.
2. Description of the Related Art
Generally, an organic light-emitting display (“OLED”) device displays images by electrically exciting an organic material. The OLED device includes a hole injection electrode (or anode), an electron injection electrode (or cathode), and an organic light-emitting layer formed therebetween. When a voltage is applied to the anode and the cathode, holes and electrons are injected into the organic light-emitting layer and recombined in the organic light-emitting layer, thereby generating excitons. The OLED device emits light by energy generated when the excitons transition to a ground state from an excited state. The organic light-emitting layer further includes an electron transport layer, a hole transport layer, an electron injection layer, and a hole injection layer to improve the brightness efficiency of the organic light-emitting layer.
The OLED devices are classified into either a top emission type or a bottom emission type depending on the direction in which light generated from the organic light-emitting layer is emitted.
Since a high-resolution OLED device is in demanded, the top emission type OLED device having a high aperture ratio is increasingly being developed. In the top emission type OLED device, light is emitted not through a lower transparent electrode and a substrate, but rather through an upper transparent or semitransparent common electrode.
The common electrode may be a transflective film formed by thinly depositing a metal or an alloy thereof, or may be formed of a transparent conductive material such as indium tin oxide (“ITO”) or indium zinc oxide (“IZO”).
When the common electrode is formed of the transflective film, a desirable transmittance may be obtained. However, it is difficult to use the thinly formed film as an electrode due to a large resistance. Furthermore, when the common electrode is formed of the transparent conductive oxide material, an electric resistance is remarkably increased relative to the metal.
The OLED device may exhibit a voltage drop caused by a resistance component as its size is increased, thereby brightly displays images at edge portions and darkly displaying images at center portions. To resolve this problem, an auxiliary electrode line is further provided to a lower thin film transistor array to supply a power voltage to the OLED device. However, since the auxiliary electrode line is formed before forming the organic light-emitting layer, masking and patterning processes must be performed several times so as not to cover the auxiliary electrode line with an organic material whenever each layer of the organic light-emitting layer is formed.